This invention relates to a programmed fluid sampling and analysis apparatus and method. More particularly, this invention relates to such a method and apparatus which includes a programmer controlled sampling of a fluid stream to subject a sample of the fluid stream to an automated analysis of the ion concentrations of the chemicals of the sampled fluid. Still more particularly, this invention relates to novel fluid sampling and reagent sampling devices for transporting sampled fluid and reagents to a novel reaction chamber which devices and chamber cooperate with other components of the programmed apparatus to provide the above-mentioned programmed automated analysis.
It has long been an aim in the art to automate the analysis of fluid samples. Accordingly, a number of such automated instruments have been developed utilizing a wide variety of approaches. In the main, however, such devices have been deficient in automating, on a low maintenance basis, the transport of sampled fluids and reagents to a reaction zone.
For example, other apparatuses for sampling fluid streams which have been devised have usually employed either peristaltic pumps or liquid sampling valves with sliding surfaces in contact with each other, and have thus embodied certain disadvantages. In such devices of the type wherein discrete quantities of the fluid stream were sampled, the polished surfaces of the sampling valve generally used in such apparatuses were often scratched with suspended matter thus causing leaks and other maintenance difficulties.
Moreover, in prior art devices wherein a continuous process stream type sampling was used, the suspended matter in the process stream often became embedded in the walls of the peristaltic pump, eventually causing pump tubing failure. Furthermore, the suspended matter would accumulate in the tubing used for transporting the fluid from the pump to the reaction or holding chambers used in the analysis, eventually causing plugging of the interconnecting tubing. Still further, the pump tubing in the peristaltic pump in such apparatuses often fatigues and cracks after extended use, thus necessitating periodic replacement of the tubing.
Some of the above-mentioned objections were overcome by the automatic analyzer disclosed in U.S. Pat. No. 3,627,494, issued Dec. 14, 1971. However, in this device, suspended matter would accumulate in the colorimeter chamber and in the liquid traps formed by the interconnecting tubing and passages and the colorimeter and reaction chamber could not be combined to decrease the response time of the instrument. This occurred because, in the described device, incoming air continued to flow into the reaction chamber which made impractical the reading of transmitted light changes as the air bubbles passed through the liquid and intercepted the light beam.
For further background for devices of the general type described, reference may be also made to U.S. Pat. No. 3,654,113 by the same inventor as in this invention. That disclosure is herein incorporated by reference.
It is, therefore, the broad object of this invention to utilize a programmer in conjunction with a novel sampling device for both the fluid stream and a reagent which includes no sliding or flexed surfaces and further utilizing measurement instrumentation for automatically programming an aliquot of a stream of fluid and several other reagent fluids through the system and for providing sequencing of the measurement instrumentation in a special discrete sampling technique.
It is another broad object of the invention to utilize such sampling devices which would prevent failure of the system due to precipitation of suspended solids into the interconnecting tubing and reaction containers.
It is still another object of this invention to provide a novel fluid sampling and transport device for use in an automated analyzer to provide a predetermined increment of sampled fluid without moving parts in contact with the liquid phases.
It is an additional object of this invention to provide such a novel sampling and transport device which does not require the flexing of passages or tubing.
It is a further object of this invention to provide a novel reagent sampling and transport device having the advantageous characteristics of the fluid sampling and transport device mentioned above.
It is still another object of this invention to provide a novel means for reacting and draining liquid mixtures for use in an automated analyzer.
It is still another object of this invention to provide such a novel means for reacting and draining liquid mixtures without moving valves or pumps or flexing surfaces in contact with the samples or reagents and particularly such a device wherein the combined liquid phase can be suspended in an elevated reaction chamber supported by air and liquid.
These and other objects of the invention will become apparent from a review of the accompanying written description of the invention taken in conjunction with the accompanying drawings.